Abstract:
Introduction
Stresza Systems Global tech a specialty Geo Tech and PT organization from Visakhapatnam got invited to investigate the possible deep excavation techniques for ongoing Mumbai City MEGA drinking water project.
Stresza has to analyze the possibility of changing previous proposed sheet piling which was practically not feasible due to the existing soil strata for driving the sheet piles. Thus Stresza came up with an innovative idea of introducing micro piles wall to replace the sheet pile wall.
In this paper we discuss about the purpose, basic design, detailed design approaches and actual work implementation of micro pile with temporary struts for shoring protection works in this project.
Micro Piles
Micro piles as well known for their application of substructure stabilization are utilized for the special application. In this project micro pile are formed as a long wall with steel waler and capping beams to provide free and secured space for the purpose of facilitating safe installation of driniking water pipe line and relation construction activities.
The sequence of work as follows:
- Site investigation for micro pile feasibility study
- Technical proposal to the clients and owner MCGM (Municipal Corporation Greater Mumbai)
- Engineering
- Survey Marking for micro pile as per design spacing with spacing gap clear 300 mm c/c
- Execute micro pile by drilling, temporary casing, permanent casing partial grouting and concrete work
- Once micro pile of done, capping beam reinforcement installed and casting done. Then excavation carried for a depth of 1.000 m is excavated and steel waler and strut installed. Note: (capping beam will be merged with back filled new road construction above it)
- Ring beam step is continued till actual level of well starting point.
- Steel waler at 1m level is done. Then further excavation is done to maximum level of 5.50 m to start the PCC and pipe line installation works
- Pipe line further covered by RCC structures then embedded in to the back filling.
- The micro pile circular wall will act like a temporary FORM WORK and permanent protection for pile line structure.
We will be discussing the following points in detailed in our paper:
- Introduction
- Micro pile with strut composite schemes
- Design of micro pile wall group
- Components of the micro pile system
- Step by step construction sequence micro piles
- Design issues
- Method of construction
- Construction issues and challenges
Abstract: Theme 1